1. Field of the Invention
The present general inventive concept relates to a molding apparatus and method of ejecting a molded article, and more particularly, to a molding apparatus and method which has an improved structure and mechanism to eject a molded article.
2. Description of the Related Art
In general, an injection molding apparatus includes a fixed mold to which an injection nozzle is attached, a movable mold which forms a cavity corresponding to an article with the fixed mold and which is installed so as to be moved relative to the fixed mold, and an ejector provided at the movable mold for ejecting the molded article from a core of the movable mold.
Hereinafter, the description of the ejector of the molding apparatus that separates the molded article from the core of the movable mold will be provided.
As disclosed in Japanese Laid-Open Publication No. H5-200806, a conventional molding apparatus includes an ejector pin movably provided for ejecting the molded article and an ejector sleeve movably provided for pushing a protruding part sticking out from a flat part of the molded article.
The ejector pin and the ejector sleeve of the conventional molding apparatus are moved to protrude to an outside of a shape surface of the core such that the molded article is completely separated from the shape surface of the core.
The conventional ejector sleeve is formed to be thinner than the ejector pin, even though its thickness is varied according to a shape of the protruding part of the molded article. And the ejector sleeve pushes the protruding part of the article toward the outside of the shape surface of the core to eject the protruding part of the molded article. Therefore, the protruding part sticking out from an inner surface of the molded article can be readily ejected from the shape surface of the core.
However, the conventional ejector sleeve of the molding apparatus protrudes to the outside of the shape surface of the core in order to push the protruding part of the article toward the outside of the shape surface of the core, so there is a possibility to damage an end portion of the ejector sleeve protruding from the shape surface of the core to be bent due to a pressing force exerted on the molded article. Further, damage can be caused to the molded article by a bent portion of the ejector sleeve, and to the shape surface of the core when the ejector sleeve is withdrawn inside the shape surface of the core while remaining bent.